Objective: To define the changes in sodium levels of Australian fast foods between 2009 and 2012 overall, in major food subcategories and by company. Design: A comparison of mean sodium content was made across 4 years using t tests and mixed models. Setting: Nutrient content data for fast-food menu items collected from company websites of six large Australian fast-food chains. Main outcome measures: Mean sodium values in mg/100 g and mg/serve. Results: There were between 302 and 381 products identified each year. Overall, the mean sodium content of fast-food products decreased between 2009 and 2012 by 43 mg/100 g (95% CI, - 66 to - 20 mg/100 g), from 514 mg/100 g in 2009 to 471 mg/100 g in 2012. Mean sodium content per serving was not significantly different at 654 mg in 2009 and 605 mg in 2012 (- 49 mg; 95% CI, - 108 to + 10 mg), reflecting wide variation in the serving sizes of items offered each year. There was a small decline in sodium content over the 4 years across most food categories and food companies. Conclusions: The observed reduction in the sodium content of fast foods during the 4-year study period is encouraging. However, the reductions are small, and fast-food companies should be encouraged to make further and larger reductions since many products still contain high levels of sodium.